The High Court ruled that Gardaí did not have to prove that every item underlying a reasonable suspicion of arrest had been lawfully obtained. It also held that Gardaí may seek fingerprints or other samples with a person’s consent. The ruling answered questions referred by a District Court judge; it did not decide whether John Cash voluntarily consented or whether the fingerprint evidence was admissible at his trial.
The case arose from a burglary at a home on Kylemore Road, Dublin, on 21 July 2003. Finger marks found on broken glass were matched by computer to fingerprints held in the Garda Technical Bureau from an earlier arrest. Gardaí arrested Cash at his home in Ballyfermot on 23 September 2003 and obtained another set of fingerprints after he indicated willingness. His mother signed the consent form because, the judgment says, he was under 18. The new prints matched those from the burglary scene.
At the District Court hearing, Garda evidence was that the earlier prints’ history could not be confirmed: officers could not say whether they had been taken with consent or under statutory powers that carried destruction requirements. A sergeant also said it was Garda policy to seek consent before asking a superintendent for an order, and that the prints would be obtained “one way or another”. The defence challenged whether the arrest and later evidence could lawfully rely on the earlier prints, and whether consent to the new prints was voluntary.
The District Court judge considered the prosecution evidence admissible and that Cash had a case to answer, but stated the case to the High Court because she was uncertain. Justice Charleton said a reasonable suspicion need not rest solely on evidence that would itself be admissible at trial or be proved to have been lawfully obtained. Uncertainty about the earlier prints’ provenance therefore did not, by itself, make the arrest or evidence obtained during detention unlawful.
He also concluded that Gardaí could seek forensic samples with consent, independently of statutory powers for taking samples from detainees. A signed form is evidence of consent, but the judge assessing the case must decide whether consent was in fact given. If evidence was lawfully obtained, the exclusion rule in *The People (DPP) v Kenny* did not apply; if a mistake infringed an identifiable constitutional right, the rule required exclusion.
The judgment’s final answers did not determine whether Cash’s consent was voluntary or direct the District Court to admit the prints. That assessment remained for the District Court. Justice Charleton also said that court was bound by *Kenny* and that the decision should not be extended to require proof that every part of an investigation complied with statutory powers.